HF019
Stream discharge in gauged watersheds at Fox Creek within the Bull Run Municipal Watershed, 1957 to 1988

CREATOR(S): Julia A. Jones, Jack S. Rothacher

PRINCIPAL INVESTIGATOR(S): Julia A. Jones

ORIGINATOR(S): Jack S. Rothacher

OTHER RESEARCHER(S): R. Dennis Harr

DATA SET CONTACT PERSON: Donald L. Henshaw

FORMER INVESTIGATOR: Richard L. Fredriksen, Alfred B. Levno

DATA SET CREDIT:

All work was carried out by the U.S. Forest Service Pacific Northwest Research Station, Watershed Project, Corvallis, Oregon, from 1958 until 1985. The Portland Water Bureau maintained these gauges over the remaining three years of this study.

MOST RECENT METADATA REVIEW DATE:

8 Feb 2017

KEYWORDS:

Disturbance, hydrology, silviculture, disturbance, hydrologic processes, streamflow, peak flows, low flows, timber harvest, water, forest ecosystems, watersheds, long term studies

PURPOSE:

Three experimental watersheds in the City of Portland's Bull Run Municipal Watershed were used to determine effects of patch logging on timing and quantity of streamflow. The objective of this study was to determine the effects of timber harvest on annual water yield, low flows, and instantaneous peak flows in small headwater basins. A pre-treatment period of no logging and the use of one control watershed are used for analysis in this paired watershed study.

METHODS:

Experimental Design - HF019:

Description:

Three adjacent watersheds in the Fox Creek drainage were gaged for streamflow masurement, Two watersheds were logged in patches and one was left as an unlogged control. In this study, relationships developed between logged and unlogged watersheds during a prelogging calibration period were used as the bases for evaluating changes in annual water yield, low flows, and instantaneous peak flows after logging.

In August 1965, a 1-km all-weather road was completed across gentle topography in FC-1 and FC-2 to the south boundary of FC-3 (fig. 1). In addition, short temporary spur roads were built into the areas to be logged in FC-1 and in FC-3. In FC-1, timber was clearcut in four units of 3-4 ha in late spring of 1969, and high-lead yarding was completed in July. logging residue in the four logged units was burned in the fall of 1970. Logging in FC-3 occurred over a 3-year period; cutting in two units of 8-10 ha began in the summer of 1970, and yarding was completed in August 1972. Both tractors and a high-lead cable system were used to yard logs. No residue was burned in FC-3. Logged area in each watershed constitutes 25 percent of the total watershed.

Citation: Harr, R. Dennis. 1980. Streamflow after patch logging in small drainages within the Bull Run Municipal Watershed, Oregon. Res. Pap. PNW-268. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 16 p.

Field Methods - HF019:

Description: Stream discharge is measured continuously on three small gauged watersheds using trapezoidal flumes. The records of stage are converted to stream discharge by applying flume-specific rating curves (ln y = lna + b ln x, where y = discharge in cubic feet per second, x= gage height in feet). Parameter values are FC01: lna=2.7428191, b=1.6318170; FC02: lna=2.8526716, b=1.6203147; FC03: lna=2.7568269, b=1.6989745. Historically, sites were visited on a 3-week basis and "check sheets" guided the data collection and maintenance activities for the visit. The instrumentation used to measure and record stream stage has been primarily Leopold-Stevens A-35 (A-71) chart recorders that were later digitized. Fischer-Porter punched tape recorders were used in lieu of charts from 1967 to 1975, although A-35 charts were still collected from FC01 during this period. The discharge measurement was re-initialized every visit to a reference measurement of stream height taken by a hook gage located in an additional stilling well. All work was carried out by the U.S. Forest Service Pacific Northwest Research Station, Watershed Project, from 1958 until 1985. The Portland Water Bureau maintained these gauges over the remaining three years of this study.

Instrumentation: Stevens Type A (A-35 or A-71) recorders, Fischer-Porter punched tape recorders

Processing Procedures - HF019:

Description: Beginning with WY 1958, all A-35 charts from the Stevens recorder were digitized at the Coweeta Hydrological Lab. In the final years of processing, the process was moved in 1986 to the Corvallis FSL using a Summagraphics MM1812 digitizer. Consistent digitizing practices were maintained throught this study. From WY 1967 through WY 1975, punched tape output was used as the raw record instead of the A-35 charts. This resulted in 15 minute data output during this period. A-35 chart digitizing resumed after WY 1975.

Instrumentation: SummaGraphics 1812 digitizer is able to record up to 40 linear points per mm at highest precision. In practice the digitizer was able to produce raw data points of stage height within .003 ft.

SITE DESCRIPTION:

The watersheds, which are designated Fox Creek 1 (FC-1), Fox Creek 2 (FC-2), and Fox Creek 3 (FC-3), are 59 ha, 253 ha, and 71 ha in size. Sideslope gradients of the watersheds average only 5-9 percent but range up to 60 percent near the watersheds' outlets. The relatively gentle topography is representative of perhaps 25-30 percent of the Bull Run Municipal Watershed. Elevation ranges from 840 m to 1070 m.

TAXONOMIC SYSTEM:

None

GEOGRAPHIC EXTENT:

The study area consists of three small watersheds in the Fox Creek drainage, a tributary to the South Fork Bull Run River, 40 km east of Portland, Oregon

ELEVATION_MINIMUM (meters):

840

ELEVATION_MAXIMUM (meters):

1070

MEASUREMENT FREQUENCY:

Continuous

PROGRESS DESCRIPTION:

Complete

UPDATE FREQUENCY DESCRIPTION:

notPlanned

CURRENTNESS REFERENCE:

Ground condition